Secale cereale, commonly known as Rye, is grown worldwide, typically for the production of grain. The grain is used primarily for making flour, bread and for direct consumption, particularly in those countries having a history of rye-bread consumption. The vegetative portions of S. cereale may be used as straw, or converted to silage, for use as animal fodder, including for in situ grazing.
As noted above, rye is mainly grown for grain. Therefore, effective pest protection during cultivation is required to ensure that a good quantity of acceptable quality grain is produced. Rye is typically considered an autumnal crop with seeds generally sown in the fall. Crop rotation with other cereals or field crops can be used to reduce the build-up of pests and/or fungal diseases present in soil or that develop in crop debris.
Principal pests of rye include, but are not limited to, aphids; thrips; wireworms and white grubs; leatherjackets (Tipula spp.); wheat bulb fly (Delia coarctata); leaf miners (Agromyza spp.); frit fly (Oscinella frit); ground beetle (Zabrus tenebrioides); saddle gall midge (Haplodiplosis marginata); cereal leaf beetles (Oulema melanopus, O. gallaeciana); nematodes; and slugs.
Known methods of pest control for rye include some or all of the following practices: the use of pest resistant cultivars, optimizing time of planting and planting with healthy seeds, effective crop rotation, destruction, and/or burial or removal of crop debris (stubble). Additional methods of pest control that may be required include the use of various pesticides on plants and/or seeds. At times, simultaneous application of two or more active substances may be required for the control of pests.
However, the use of many pesticides can be problematic due to the known problems associated with the chemicals frequently used for such purposes. Many pesticides are toxic and can be dangerous to human and animal consumers of treated agricultural crops (Casida and Quistad, 1998). In particular, the accumulation, in humans and animals of toxic pesticides can lead to serious health issues for individuals, particularly during early development. For example, pesticide exposure has been linked to respiratory disorders, developmental cancers and shown to have lasting effects on the development of mental abilities Zejda et al. (1993).
The use of pesticides may be difficult to control in variable environmental conditions leading to unwanted dispersal of toxic compounds, for example by drift of sprays or by soil leaching. In addition, the pests may develop pesticide resistance for a number of reasons, including improper practice and handling, which can pose a real threat to crop (grain) yields. Accordingly there is a need for pest control measures that do not use applied pesticides.
It is an object of the present invention to provide at least one epichloae fungal endophyte strain which when combined with at least one species of Secale spp. confers at least some level of pest protection on the Secale spp. plant, and/or to provide the public with a useful choice.
In this specification where reference has been made to patent specifications, other external documents, or other sources of information, this is generally for the purpose of providing a context for discussing the features of the invention. Unless specifically stated otherwise, reference to such external documents is not to be construed as an admission that such documents, or such sources of information, in any jurisdiction, are prior art, or form part of the common general knowledge in the art.